Did I change when I added seed to my survival world?
What are you asking?
The seed you input when starting the world determines how Minecraft creates the world.
It's still basically random just that 2 worlds created using the same seed will be the same as long as they were created in the same version of Minecraft.
So if you find an interesting place to build a base you can tell somebody else what the seed is so they can use that in their world as well.
(Not everything is going to be exactly identical, some things can vary a bit depending on in which order the chunks are created.)
What? you mean your world got updated when you update Minecraft or you cant use the seed anymore? because you updated Minecraft?.